package parser import ( "github.com/robertkrimen/otto/ast" "github.com/robertkrimen/otto/token" ) func (self *_parser) parseBlockStatement() *ast.BlockStatement { node := &ast.BlockStatement{} // Find comments before the leading brace if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, self.comments.FetchAll(), ast.LEADING) self.comments.Unset() } node.LeftBrace = self.expect(token.LEFT_BRACE) node.List = self.parseStatementList() if self.mode&StoreComments != 0 { self.comments.Unset() self.comments.CommentMap.AddComments(node, self.comments.FetchAll(), ast.FINAL) self.comments.AfterBlock() } node.RightBrace = self.expect(token.RIGHT_BRACE) // Find comments after the trailing brace if self.mode&StoreComments != 0 { self.comments.ResetLineBreak() self.comments.CommentMap.AddComments(node, self.comments.Fetch(), ast.TRAILING) } return node } func (self *_parser) parseEmptyStatement() ast.Statement { idx := self.expect(token.SEMICOLON) return &ast.EmptyStatement{Semicolon: idx} } func (self *_parser) parseStatementList() (list []ast.Statement) { for self.token != token.RIGHT_BRACE && self.token != token.EOF { statement := self.parseStatement() list = append(list, statement) } return } func (self *_parser) parseStatement() ast.Statement { if self.token == token.EOF { self.errorUnexpectedToken(self.token) return &ast.BadStatement{From: self.idx, To: self.idx + 1} } if self.mode&StoreComments != 0 { self.comments.ResetLineBreak() } switch self.token { case token.SEMICOLON: return self.parseEmptyStatement() case token.LEFT_BRACE: return self.parseBlockStatement() case token.IF: return self.parseIfStatement() case token.DO: statement := self.parseDoWhileStatement() self.comments.PostProcessNode(statement) return statement case token.WHILE: return self.parseWhileStatement() case token.FOR: return self.parseForOrForInStatement() case token.BREAK: return self.parseBreakStatement() case token.CONTINUE: return self.parseContinueStatement() case token.DEBUGGER: return self.parseDebuggerStatement() case token.WITH: return self.parseWithStatement() case token.VAR: return self.parseVariableStatement() case token.FUNCTION: return self.parseFunctionStatement() case token.SWITCH: return self.parseSwitchStatement() case token.RETURN: return self.parseReturnStatement() case token.THROW: return self.parseThrowStatement() case token.TRY: return self.parseTryStatement() } var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } expression := self.parseExpression() if identifier, isIdentifier := expression.(*ast.Identifier); isIdentifier && self.token == token.COLON { // LabelledStatement colon := self.idx if self.mode&StoreComments != 0 { self.comments.Unset() } self.next() // : label := identifier.Name for _, value := range self.scope.labels { if label == value { self.error(identifier.Idx0(), "Label '%s' already exists", label) } } var labelComments []*ast.Comment if self.mode&StoreComments != 0 { labelComments = self.comments.FetchAll() } self.scope.labels = append(self.scope.labels, label) // Push the label statement := self.parseStatement() self.scope.labels = self.scope.labels[:len(self.scope.labels)-1] // Pop the label exp := &ast.LabelledStatement{ Label: identifier, Colon: colon, Statement: statement, } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(exp, labelComments, ast.LEADING) } return exp } self.optionalSemicolon() statement := &ast.ExpressionStatement{ Expression: expression, } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(statement, comments, ast.LEADING) } return statement } func (self *_parser) parseTryStatement() ast.Statement { var tryComments []*ast.Comment if self.mode&StoreComments != 0 { tryComments = self.comments.FetchAll() } node := &ast.TryStatement{ Try: self.expect(token.TRY), Body: self.parseBlockStatement(), } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, tryComments, ast.LEADING) self.comments.CommentMap.AddComments(node.Body, self.comments.FetchAll(), ast.TRAILING) } if self.token == token.CATCH { catch := self.idx if self.mode&StoreComments != 0 { self.comments.Unset() } self.next() self.expect(token.LEFT_PARENTHESIS) if self.token != token.IDENTIFIER { self.expect(token.IDENTIFIER) self.nextStatement() return &ast.BadStatement{From: catch, To: self.idx} } else { identifier := self.parseIdentifier() self.expect(token.RIGHT_PARENTHESIS) node.Catch = &ast.CatchStatement{ Catch: catch, Parameter: identifier, Body: self.parseBlockStatement(), } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node.Catch.Body, self.comments.FetchAll(), ast.TRAILING) } } } if self.token == token.FINALLY { if self.mode&StoreComments != 0 { self.comments.Unset() } self.next() if self.mode&StoreComments != 0 { tryComments = self.comments.FetchAll() } node.Finally = self.parseBlockStatement() if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node.Finally, tryComments, ast.LEADING) } } if node.Catch == nil && node.Finally == nil { self.error(node.Try, "Missing catch or finally after try") return &ast.BadStatement{From: node.Try, To: node.Body.Idx1()} } return node } func (self *_parser) parseFunctionParameterList() *ast.ParameterList { opening := self.expect(token.LEFT_PARENTHESIS) if self.mode&StoreComments != 0 { self.comments.Unset() } var list []*ast.Identifier for self.token != token.RIGHT_PARENTHESIS && self.token != token.EOF { if self.token != token.IDENTIFIER { self.expect(token.IDENTIFIER) } else { identifier := self.parseIdentifier() list = append(list, identifier) } if self.token != token.RIGHT_PARENTHESIS { if self.mode&StoreComments != 0 { self.comments.Unset() } self.expect(token.COMMA) } } closing := self.expect(token.RIGHT_PARENTHESIS) return &ast.ParameterList{ Opening: opening, List: list, Closing: closing, } } func (self *_parser) parseParameterList() (list []string) { for self.token != token.EOF { if self.token != token.IDENTIFIER { self.expect(token.IDENTIFIER) } list = append(list, self.literal) self.next() if self.token != token.EOF { self.expect(token.COMMA) } } return } func (self *_parser) parseFunctionStatement() *ast.FunctionStatement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } function := &ast.FunctionStatement{ Function: self.parseFunction(true), } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(function, comments, ast.LEADING) } return function } func (self *_parser) parseFunction(declaration bool) *ast.FunctionLiteral { node := &ast.FunctionLiteral{ Function: self.expect(token.FUNCTION), } var name *ast.Identifier if self.token == token.IDENTIFIER { name = self.parseIdentifier() if declaration { self.scope.declare(&ast.FunctionDeclaration{ Function: node, }) } } else if declaration { // Use expect error handling self.expect(token.IDENTIFIER) } if self.mode&StoreComments != 0 { self.comments.Unset() } node.Name = name node.ParameterList = self.parseFunctionParameterList() self.parseFunctionBlock(node) node.Source = self.slice(node.Idx0(), node.Idx1()) return node } func (self *_parser) parseFunctionBlock(node *ast.FunctionLiteral) { { self.openScope() inFunction := self.scope.inFunction self.scope.inFunction = true defer func() { self.scope.inFunction = inFunction self.closeScope() }() node.Body = self.parseBlockStatement() node.DeclarationList = self.scope.declarationList } } func (self *_parser) parseDebuggerStatement() ast.Statement { idx := self.expect(token.DEBUGGER) node := &ast.DebuggerStatement{ Debugger: idx, } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, self.comments.FetchAll(), ast.TRAILING) } self.semicolon() return node } func (self *_parser) parseReturnStatement() ast.Statement { idx := self.expect(token.RETURN) var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } if !self.scope.inFunction { self.error(idx, "Illegal return statement") self.nextStatement() return &ast.BadStatement{From: idx, To: self.idx} } node := &ast.ReturnStatement{ Return: idx, } if !self.implicitSemicolon && self.token != token.SEMICOLON && self.token != token.RIGHT_BRACE && self.token != token.EOF { node.Argument = self.parseExpression() } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, comments, ast.LEADING) } self.semicolon() return node } func (self *_parser) parseThrowStatement() ast.Statement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } idx := self.expect(token.THROW) if self.implicitSemicolon { if self.chr == -1 { // Hackish self.error(idx, "Unexpected end of input") } else { self.error(idx, "Illegal newline after throw") } self.nextStatement() return &ast.BadStatement{From: idx, To: self.idx} } node := &ast.ThrowStatement{ Argument: self.parseExpression(), } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, comments, ast.LEADING) } self.semicolon() return node } func (self *_parser) parseSwitchStatement() ast.Statement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } self.expect(token.SWITCH) if self.mode&StoreComments != 0 { comments = append(comments, self.comments.FetchAll()...) } self.expect(token.LEFT_PARENTHESIS) node := &ast.SwitchStatement{ Discriminant: self.parseExpression(), Default: -1, } self.expect(token.RIGHT_PARENTHESIS) if self.mode&StoreComments != 0 { comments = append(comments, self.comments.FetchAll()...) } self.expect(token.LEFT_BRACE) inSwitch := self.scope.inSwitch self.scope.inSwitch = true defer func() { self.scope.inSwitch = inSwitch }() for index := 0; self.token != token.EOF; index++ { if self.token == token.RIGHT_BRACE { self.next() break } clause := self.parseCaseStatement() if clause.Test == nil { if node.Default != -1 { self.error(clause.Case, "Already saw a default in switch") } node.Default = index } node.Body = append(node.Body, clause) } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, comments, ast.LEADING) } return node } func (self *_parser) parseWithStatement() ast.Statement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } self.expect(token.WITH) var withComments []*ast.Comment if self.mode&StoreComments != 0 { withComments = self.comments.FetchAll() } self.expect(token.LEFT_PARENTHESIS) node := &ast.WithStatement{ Object: self.parseExpression(), } self.expect(token.RIGHT_PARENTHESIS) if self.mode&StoreComments != 0 { //comments = append(comments, self.comments.FetchAll()...) self.comments.CommentMap.AddComments(node, comments, ast.LEADING) self.comments.CommentMap.AddComments(node, withComments, ast.WITH) } node.Body = self.parseStatement() return node } func (self *_parser) parseCaseStatement() *ast.CaseStatement { node := &ast.CaseStatement{ Case: self.idx, } var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() self.comments.Unset() } if self.token == token.DEFAULT { self.next() } else { self.expect(token.CASE) node.Test = self.parseExpression() } if self.mode&StoreComments != 0 { self.comments.Unset() } self.expect(token.COLON) for { if self.token == token.EOF || self.token == token.RIGHT_BRACE || self.token == token.CASE || self.token == token.DEFAULT { break } consequent := self.parseStatement() node.Consequent = append(node.Consequent, consequent) } // Link the comments to the case statement if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, comments, ast.LEADING) } return node } func (self *_parser) parseIterationStatement() ast.Statement { inIteration := self.scope.inIteration self.scope.inIteration = true defer func() { self.scope.inIteration = inIteration }() return self.parseStatement() } func (self *_parser) parseForIn(into ast.Expression) *ast.ForInStatement { // Already have consumed " in" source := self.parseExpression() self.expect(token.RIGHT_PARENTHESIS) body := self.parseIterationStatement() forin := &ast.ForInStatement{ Into: into, Source: source, Body: body, } return forin } func (self *_parser) parseFor(initializer ast.Expression) *ast.ForStatement { // Already have consumed " ;" var test, update ast.Expression if self.token != token.SEMICOLON { test = self.parseExpression() } if self.mode&StoreComments != 0 { self.comments.Unset() } self.expect(token.SEMICOLON) if self.token != token.RIGHT_PARENTHESIS { update = self.parseExpression() } self.expect(token.RIGHT_PARENTHESIS) body := self.parseIterationStatement() forstatement := &ast.ForStatement{ Initializer: initializer, Test: test, Update: update, Body: body, } return forstatement } func (self *_parser) parseForOrForInStatement() ast.Statement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } idx := self.expect(token.FOR) var forComments []*ast.Comment if self.mode&StoreComments != 0 { forComments = self.comments.FetchAll() } self.expect(token.LEFT_PARENTHESIS) var left []ast.Expression forIn := false if self.token != token.SEMICOLON { allowIn := self.scope.allowIn self.scope.allowIn = false if self.token == token.VAR { var_ := self.idx var varComments []*ast.Comment if self.mode&StoreComments != 0 { varComments = self.comments.FetchAll() self.comments.Unset() } self.next() list := self.parseVariableDeclarationList(var_) if len(list) == 1 && self.token == token.IN { if self.mode&StoreComments != 0 { self.comments.Unset() } self.next() // in forIn = true left = []ast.Expression{list[0]} // There is only one declaration } else { left = list } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(left[0], varComments, ast.LEADING) } } else { left = append(left, self.parseExpression()) if self.token == token.IN { self.next() forIn = true } } self.scope.allowIn = allowIn } if forIn { switch left[0].(type) { case *ast.Identifier, *ast.DotExpression, *ast.BracketExpression, *ast.VariableExpression: // These are all acceptable default: self.error(idx, "Invalid left-hand side in for-in") self.nextStatement() return &ast.BadStatement{From: idx, To: self.idx} } forin := self.parseForIn(left[0]) if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(forin, comments, ast.LEADING) self.comments.CommentMap.AddComments(forin, forComments, ast.FOR) } return forin } if self.mode&StoreComments != 0 { self.comments.Unset() } self.expect(token.SEMICOLON) initializer := &ast.SequenceExpression{Sequence: left} forstatement := self.parseFor(initializer) if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(forstatement, comments, ast.LEADING) self.comments.CommentMap.AddComments(forstatement, forComments, ast.FOR) } return forstatement } func (self *_parser) parseVariableStatement() *ast.VariableStatement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } idx := self.expect(token.VAR) list := self.parseVariableDeclarationList(idx) statement := &ast.VariableStatement{ Var: idx, List: list, } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(statement, comments, ast.LEADING) self.comments.Unset() } self.semicolon() return statement } func (self *_parser) parseDoWhileStatement() ast.Statement { inIteration := self.scope.inIteration self.scope.inIteration = true defer func() { self.scope.inIteration = inIteration }() var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } self.expect(token.DO) var doComments []*ast.Comment if self.mode&StoreComments != 0 { doComments = self.comments.FetchAll() } node := &ast.DoWhileStatement{} if self.token == token.LEFT_BRACE { node.Body = self.parseBlockStatement() } else { node.Body = self.parseStatement() } self.expect(token.WHILE) var whileComments []*ast.Comment if self.mode&StoreComments != 0 { whileComments = self.comments.FetchAll() } self.expect(token.LEFT_PARENTHESIS) node.Test = self.parseExpression() self.expect(token.RIGHT_PARENTHESIS) if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, comments, ast.LEADING) self.comments.CommentMap.AddComments(node, doComments, ast.DO) self.comments.CommentMap.AddComments(node, whileComments, ast.WHILE) } return node } func (self *_parser) parseWhileStatement() ast.Statement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } self.expect(token.WHILE) var whileComments []*ast.Comment if self.mode&StoreComments != 0 { whileComments = self.comments.FetchAll() } self.expect(token.LEFT_PARENTHESIS) node := &ast.WhileStatement{ Test: self.parseExpression(), } self.expect(token.RIGHT_PARENTHESIS) node.Body = self.parseIterationStatement() if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, comments, ast.LEADING) self.comments.CommentMap.AddComments(node, whileComments, ast.WHILE) } return node } func (self *_parser) parseIfStatement() ast.Statement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } self.expect(token.IF) var ifComments []*ast.Comment if self.mode&StoreComments != 0 { ifComments = self.comments.FetchAll() } self.expect(token.LEFT_PARENTHESIS) node := &ast.IfStatement{ Test: self.parseExpression(), } self.expect(token.RIGHT_PARENTHESIS) if self.token == token.LEFT_BRACE { node.Consequent = self.parseBlockStatement() } else { node.Consequent = self.parseStatement() } if self.token == token.ELSE { self.next() node.Alternate = self.parseStatement() } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(node, comments, ast.LEADING) self.comments.CommentMap.AddComments(node, ifComments, ast.IF) } return node } func (self *_parser) parseSourceElement() ast.Statement { statement := self.parseStatement() //self.comments.Unset() return statement } func (self *_parser) parseSourceElements() []ast.Statement { body := []ast.Statement(nil) for { if self.token != token.STRING { break } body = append(body, self.parseSourceElement()) } for self.token != token.EOF { body = append(body, self.parseSourceElement()) } return body } func (self *_parser) parseProgram() *ast.Program { self.openScope() defer self.closeScope() return &ast.Program{ Body: self.parseSourceElements(), DeclarationList: self.scope.declarationList, File: self.file, } } func (self *_parser) parseBreakStatement() ast.Statement { var comments []*ast.Comment if self.mode&StoreComments != 0 { comments = self.comments.FetchAll() } idx := self.expect(token.BREAK) semicolon := self.implicitSemicolon if self.token == token.SEMICOLON { semicolon = true self.next() } if semicolon || self.token == token.RIGHT_BRACE { self.implicitSemicolon = false if !self.scope.inIteration && !self.scope.inSwitch { goto illegal } breakStatement := &ast.BranchStatement{ Idx: idx, Token: token.BREAK, } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(breakStatement, comments, ast.LEADING) self.comments.CommentMap.AddComments(breakStatement, self.comments.FetchAll(), ast.TRAILING) } return breakStatement } if self.token == token.IDENTIFIER { identifier := self.parseIdentifier() if !self.scope.hasLabel(identifier.Name) { self.error(idx, "Undefined label '%s'", identifier.Name) return &ast.BadStatement{From: idx, To: identifier.Idx1()} } self.semicolon() breakStatement := &ast.BranchStatement{ Idx: idx, Token: token.BREAK, Label: identifier, } if self.mode&StoreComments != 0 { self.comments.CommentMap.AddComments(breakStatement, comments, ast.LEADING) } return breakStatement } self.expect(token.IDENTIFIER) illegal: self.error(idx, "Illegal break statement") self.nextStatement() return &ast.BadStatement{From: idx, To: self.idx} } func (self *_parser) parseContinueStatement() ast.Statement { idx := self.expect(token.CONTINUE) semicolon := self.implicitSemicolon if self.token == token.SEMICOLON { semicolon = true self.next() } if semicolon || self.token == token.RIGHT_BRACE { self.implicitSemicolon = false if !self.scope.inIteration { goto illegal } return &ast.BranchStatement{ Idx: idx, Token: token.CONTINUE, } } if self.token == token.IDENTIFIER { identifier := self.parseIdentifier() if !self.scope.hasLabel(identifier.Name) { self.error(idx, "Undefined label '%s'", identifier.Name) return &ast.BadStatement{From: idx, To: identifier.Idx1()} } if !self.scope.inIteration { goto illegal } self.semicolon() return &ast.BranchStatement{ Idx: idx, Token: token.CONTINUE, Label: identifier, } } self.expect(token.IDENTIFIER) illegal: self.error(idx, "Illegal continue statement") self.nextStatement() return &ast.BadStatement{From: idx, To: self.idx} } // Find the next statement after an error (recover) func (self *_parser) nextStatement() { for { switch self.token { case token.BREAK, token.CONTINUE, token.FOR, token.IF, token.RETURN, token.SWITCH, token.VAR, token.DO, token.TRY, token.WITH, token.WHILE, token.THROW, token.CATCH, token.FINALLY: // Return only if parser made some progress since last // sync or if it has not reached 10 next calls without // progress. Otherwise consume at least one token to // avoid an endless parser loop if self.idx == self.recover.idx && self.recover.count < 10 { self.recover.count++ return } if self.idx > self.recover.idx { self.recover.idx = self.idx self.recover.count = 0 return } // Reaching here indicates a parser bug, likely an // incorrect token list in this function, but it only // leads to skipping of possibly correct code if a // previous error is present, and thus is preferred // over a non-terminating parse. case token.EOF: return } self.next() } }